Stackable cartridges for bulk feeders

ABSTRACT

A set of vertically stackable interacting cartridges for improving the delivery of biocide of a bulk feeder by positioning the stackable cartridges in a stacked condition within a chamber in the bulk feeder wherein the stackable cartridges are maintained in vertical interacting flow alignment with each other to provide enhanced control of the delivery of the biocide carried within each of the stackable cartridges without replacing the control valves of the bulk feeder.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. provisional application Ser.No. 61/628,089 filed Oct. 24, 2011.

FIELD OF THE INVENTION

This invention relates generally to dispensing cartridges and, morespecifically, to an interactive stackable cartridge system fordispensing water purification materials from a feeder such as a bulkdispenser.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None

REFERENCE TO A MICROFICHE APPENDIX

None

BACKGROUND OF THE INVENTION

One of the ways of ridding pools, spas or other bodies of water ofharmful organism is to add a halogen such as chlorine or bromine to thebody of water. Typically, the halogen may be added to the body of waterthrough a bulk feeder. In the bulk feeder tablets or pucks of chlorineor bromine are placed in a chamber of the bulk feeder where the waterflowing through the bulk feeder comes into contact with the halogenlocated therein. One of the disadvantages of the bulk feeders is that itis difficult to control the level of halogen that is dispersed into thebody of water, which often results in over chlorination or overbrominating of the body of water. While such bulk feeders are relativelyinexpensive the cost of the overuse of chlorine and or bromine in thebulk feeders can quickly negate any benefits of the bulk feeder. Toreduce the problem of over chlorination or bromination as well asimproving the control of the level of chlorine or bromine in a body ofwater other types of feeders that separately dispense two differentbiocides may be used.

One method and apparatus for controlling the harmful organisms in a bodyof water in a bulk feeder uses two dispensers that deliver two differentbiocides. Such a device is shown in King U.S. Pat. No. 7,347,935. Inthis device the two biocides are located in two separate dispensers thatare placed in a free or non-fitted condition in the chamber of a bulkfeeder. The dispensers are allowed to move about in the chamber inresponse to the fluid flow through the chamber of the feeder, whichenables the water to come into contact with the biocides locatedtherein. As the dispensers move about in the chamber of the feeder thebiocides therein are released into the water passing through the chamberof the feeder. In such devices in addition to the control valve on thefeeder the dispensers may include adjustable valves on each dispenser inorder to better control the dispersant level of each of the biocides.

Another chemical feeder for dispensing two chemicals into a pool isshown in U.S. Pat. No. 5,251,656 where two compartments containing watertreatment materials with a venturi housing to draw the water treatmentmaterials out of each of the compartments and into the pool.

U.S. Pat. No. 6,471,858 shows a dispensing apparatus where a pair ofcylindrical containers containing water treatment materials are locatedin a coaxial condition. The containers are cantileverly mounted within atop chamber in a sand filter, which allows the water to flow throughboth of the containers before flowing through a bed of sand.

Another method and apparatus for accurately delivering two biocides froma single chamber in an inline feeder is shown in King U.S. Pat. Nos.6,527,952 and 6,190,547. In this device two nestable canisters areconcentrically positioned in the chamber of an inline feeder with eachof the nestable canisters having inlets and outlets that separate theflow of water into two separate streams with each of the two streamsfollowing separate but parallel flow paths through the biocides in theirrespective nestable canisters.

Since most feeders are integrally mounted in a circulation line of abody of water such as a pool or spa the conversion of a bulk feeder to acartridge system that can accurately deliver two different biocidesbecomes costly since one may have to remove and replace the existingbulk feeder with a feeder that provides parallel flow paths through thedispensers therein. In other cases where the dispensers are free to moveabout the chamber of the feeder the task of control of the delivery rateof the biocides from the separate dispensers becomes more delicate sincein addition to adjusting the setting of the control valve of the bulkfeeder the valve of one or both of the dispensers may need to beadjusted to control the flow of water through the dispensers and hencethe level of biocide that is delivered to the body of water. Thus a needexists for a cartridge system that can be used in prior art bulk feedersto alleviate problems of over halogenation but also provide a system fordelivering two or more biocides to the body of water, which for examplemay be a pool, a spa or the like although the cartridge system may beused with any body of water which requires delivery of a biocidethereto.

In contrast to the prior art the system described herein the inventionallows one to provide dispersant control which avoids over halogenationof the body of water in existing bulk feeders and without having toseparately adjust gate valves on each of dispensers used in the bulkfeeder.

SUMMARY OF THE INVENTION

A set of inline vertically stackable cartridges for improving thedelivery of a biocide from a prior art bulk feeder using a set ofstackable cartridges located in an end to end condition within a chamberin a bulk feeder wherein the stackable cartridges are maintained in flowalignment with each other to provide an interactive flow resistance thatresults in the feeder providing enhanced control of the delivery of eachof the biocides carried therein without need to replace the controlvalve of the bulk feeder or to install a feeder with fitted cartridges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows in cross section an example of a prior art bulk halogenfeeder;

FIG. 2 shows cross section an example of another type of prior art bulkhalogen feeder;

FIG. 2A shows a swimming pool with a bulk feeder;

FIG. 3 shows a top perspective view of a stackable cartridge;

FIG. 4 shows a bottom perspective view of the stackable cartridge ofFIG. 3;

FIG. 5 shows a bottom perspective view of another stackable cartridge;

FIG. 6 shows a top perspective view of the stackable cartridge of FIG.5;

FIG. 7 shows the prior bulk halogen feeder of FIG. 1 containing thestackable cartridge of FIG. 3 and FIG. 5;

FIG. 8 is a graph of the comparative control of a halogen in a bulkfeeder with and without the cartridges therein;

FIG. 9 is a cross section view of the bulk feeder of FIG. 2 with a setof stackable cartridges located therein;

FIG. 10 is a top view of a stackable cartridge;

FIG. 11 is a front view of the stackable cartridge of FIG. 10

FIG. 12 is a bottom view of the stackable cartridge of FIG. 10

FIG. 13 is a top view of a second stackable cartridge;

FIG. 14 is a front view of the stackable cartridge of FIG. 13;

FIG. 15 is a bottom view of the stackable cartridge of FIG. 13; and

FIG. 16 shows is a cross section view of the bulk feeder of FIG. 2 witha set of three stackable cartridges located therein.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a typical example of a prior art bulk halogen feeder 10,which is sold by Hayward Industries, Inc., having a frusto conicalhousing 11 with a lower venturi 13 having an inlet 14 for directing aportion of the water flowing therethrough into a channel 15 and througha passage 16 and into chamber 20 where the water contacts the halogen21, which is in bulk form and is shown located below the water line 20 ain the chamber 20. In this example a rotateable control valve 17 allowsone to increase or decrease the amount of water flowing into chamber 20and consequently into contact with the bulk chlorine tablets 21 byreducing or increasing the spacing between valve end 17 a and passage16. Once the water contacts the halogen tablets 21 the water can flowout of chamber 20 through a fluid passage 23 a in a vertical stand tube23 and back into the venturi 13 through the port 24. A cover 27, whichis sealed to the housing 11 through an annular seal 28, normallymaintains the bulk feeder in a closed condition when the system is inuse. It is this type of feeder that is prone to over halogenationbecause the water flows freely through the halogen tablets 21 beforebeing discharged through the stand tube 23.

FIG. 2 shows another typical example of a prior art bulk halogen feeder30, which is sold by Rainbow Lifeguard Products, Inc., having acylindrical housing 31 with a lower main line fitting 32 which attachesto an inline circulating system. A side tap 33 a directs a portion ofthe water from the main line fitting 32 through a pipe 33 to a controlvalve 34, which can be used to limit the flow of water from the mainline through the chamber 35. The housing includes a cover 36 and anannular seal 37, which creates an airtight chamber 35. In operation aportion the water flowing through the main line fitting 32 flows intoside tap 33 a through pipe 33, control valve 34, pipe 42 and inlet 42 awhere it can then flow through the bulk chlorine tablets 41, which arelocated below the water line 35 a in chamber 35. The water with thedissolved halogen therein then flows out of the chamber 35 throughoutlet 43 and into the fitting 32 where it is returned to the maininline circulation system. This type of system has also been found tobecome over halogenated since the halogen tablets 41 are rapidlydissolved by the water flowing through the open chamber 35.

Briefly, in both of the above type of systems the halogen in puck ortablet form is located in the chamber of the bulk feeder while oneattempts to control the release of the halogen therefrom by using a flowvalve on the feeder to direct more or less water through the bulkhalogen tablets, which are stacked loosely and randomly in the chamberof the bulk feeder. Unfortunately, the accurate and controlled deliveryof halogen to the body of water becomes difficult when the tablets orpucks are located in the chamber in the bulk feeder since the deliveryrate is sensitive to the variable resistance offered by the dissolvablehalogen pucks or tablets as well as the number tablets or pucks that arelocated below the water line 35 a. Because of the difficulty inaccurately delivering the proper amount of halogen through bulk feederssuch as described an operator may want to ensure that a minimum amountof halogen is always available in the water, which may result in valvesettings on the feeder that causes over halogenation i.e. overchlorination or over bromination of the body of water. The above are twoexamples of bulk halogen feeders that are prone to over halogenation,however, other types of feeders may also be prone to problems of overhalogenation.

In order to better control the levels of halogen in existing bulkfeeders the invention described herein includes a set of verticallystackable cartridges that can be placed in fluid alignment in the openchamber of the prior art bulk feeders to allow an operator to moreaccurately control the level of halogen delivered to a body of watereven though only one of the vertically stackable cartridges may containa halogen in puck or tablet form. As pointed out, one of thedifficulties with bulk feeder systems that rely only on a halogen isthat the level of halogen in the system must be maintained relativelyhigh in order to ensure that the water is free of harmful organisms,which may result in the body of water having an annoying or obnoxiouschlorine or bromine smell if the water is over halogenated.

One of the ways of lowering the level of the necessary halogen in a bodyof water is to use a two bactericide system that uses a secondarybiocide material such as a source of metal ions in addition to thehalogen which allows the halogen level to be maintained at a lower levelsince the two bactericides working together can effectively kill harmfulmicroorganisms that would normally require a higher halogen level ifonly the halogen were present. The combination of the simultaneousdelivery of two biocides can be effective in maintaining a system freeof harmful organisms while at the same time reducing the obnoxiouspresence of high levels of halogens in the body of water. An example ofa two-biocide or bactericide system is shown in my U.S. Pat. No.6,527,952, which is hereby incorporated by reference. Unfortunately,such two bactericide systems require the homeowner to replace the bulkhalogen feeder with a new inline cartridge feeder in order to properlydispense and maintain the lower halogen level since the bulk feedercontrols and the open chamber in the bulk feeders are generally not wellsuited for maintaining low levels of halogen in the body of water.

The system described herein comprises a set of interacting verticallystackable cartridges that can be placed in a chamber of a bulk feeder,which normally holds halogen in bulk form, to provide a cartridge systemthat can more precisely deliver a halogen at a lower rate to the body ofwater, which allows one to maintain a lower halogen level in the body ofwater, while still maintaining the body of water in a safe conditionwith the system including the ability to adjust the valve on the bulkfeeder to maintain the chlorine level at about 0.5 ppm or lower withoutmodification of the bulk feeder.

FIG. 3 shows a top perspective view of a vertically stackable cartridge50 and FIG. 4 shows a bottom perspective view of the stackable cartridge50 for placement in a bulk feeder as part of an interacting stackabletwo cartridge system, which may be used to reduce over chlorination orover bromination in a bulk feeder that normally holds a halogen in solidform therein. Typically, lower stackable cartridge 50 contains abiocide, which may be minerals, for example, a source of metal ions suchas silver ions or copper ions. The stackable cartridge 50 comprises acylindrical container having a circular top member 51, a bottom member59 and a cylindrical side wall 52 which coact to form a chamber thereinfor holding and dispensing a biocide such as metal ions therefrom. Themetal ions such as copper ions, silver ions, or zinc ions can bedelivered from the chamber by minerals which are retained within thestackable cartridge during the dispensing process to provide arelatively fixed fluid resistance of flow through the stackablecartridge 50. Bottom member 59 includes a feature comprising adiametrical extending valley 63 with a first set of fluid passages 63 aon one side of valley 63 with the fluid passage 63 a providing a firstbottom fluid inlet to the chamber therein and a second set of fluidpassages 63 b on the opposite side of valley 63 with the fluid passages63 b providing a second bottom fluid inlet to the chamber in stackablecartridge 50.

The top member 51 includes a set of centrally positioned top fluidpassages 53 for a restrictive flow of fluid therethrough. The top fluidpassages 53 and the bottom fluid passages are sized so as to retain thesolid biocides within the chamber of the stackable cartridge 50 whileallowing water to flow into and out of the chamber in stackablecartridge 50. Located around fluid passages 53 is a cartridge support orspacer comprising a set of three axial protrusions 54, 55 and 56, whichextend upward from inner top member 57. The purpose of the support is toat least partially support a stackable cartridge there above as well asto provide a diametrical flow passage between the bottom of a topstackable cartridge 70 and the top of the bottom stackable cartridge 50.The support can thus maintain the second or top stackable cartridge in astacked but bottom spaced condition from the first stackable cartridge.In order to maintain the stackable cartridge 50 in proper operatingposition cartridge 50 includes a feature or locater 58 comprising a semihemispherical vertical notch, which engages with a vertical feature ofthe bulk feeder such as a standpipe 23 (FIG. 7) of the bulk feeder tomaintain the cartridge in a fixed rotational position therein. Inaddition the bottom of cartridge 50 includes a further feature orlocater 63 comprising a valley as well as cross-valley 61 and 62 whichare also configured so as to interact with internal features on thebottom of bulk feeder to prevent rotation of the stackable cartridge 50during the operation of the bulk feeder with the stackable cartridgeslocated therein. While the locater or feature on the stackablecartridges is shown as notches or valleys in a side of stackablecartridge 50, other types of locaters or features of the stackablecartridges may be used for engagement with features of the bulk feederto maintain the stackable cartridges in the proper orientation so thatwater can be directed through the biocide in the stackable cartridge 50.In this example the locator on the cartridge 50 and the locater 74 onthe stackable cartridge 70 are in engagement with a common feature ofthe bulk feeder, namely, the standpipe 23 of the bulk feeder to maintainthe stackable cartridge 50 and the stackable cartridge 70 in fluidalignment with each other to permit flow through the stacked cartridges50 and 70. Thus the vertically stackable cartridge system describedherein can take advantage of internal features of the bulk feeder tomaintain the stackable cartridges in a fixed rotational condition and influid alignment with each other in a bulk feeder, which can eliminatethe condition of random flow of water through the halogen which islocated in the chamber of the feeder. A further feature of the inlinestackable cartridges is the use of biocide such as a non-dissolvablesource of minerals in one of the stackable cartridges, which can also beused to both deliver a biocide and maintain an internal inline flowresistance during the delivery of the biocide to the body of water. Adissolvable biocide such as chlorine or bromine may be located in theother inline stackable cartridge.

FIG. 5 shows a bottom perspective view of a stackable cartridge 70 andFIG. 6 shows a top perspective view of the stackable cartridge 70 forstacking with the stackable cartridge 50 of FIG. 3 and FIG. 4. Thestackable cartridge 70, which typically contains a halogen, comprises acylindrical container having a circular bottom member 71, a closed topmember 73 and a cylindrical sidewall 72 which coact to form a chambertherein with an upper portion of chamber for trapping air therein andfor holding a portion of a halogen such as chlorine or bromine in solidform above a water line therein to limit the water contact with thehalogen and thus limit the dissolution rate of the halogen. The internalflow resistance of the flow path established between and withinstackable cartridges allows the existing feeder control valve on thebulk feeder to be used to deliver a halogen at a more sustainable ratethen if only halogen is located in the feeder.

Extending in an axial direction along sidewall 72 is a feature orlocater comprising an elongated hemispherical notch 74. Notch 74 engageswith a feature of the interior of the bulk feeder such as a standpipe 23(FIG. 7) to maintain the fixed rotational position of the stackablecartridge 70 with respect to the bulk feeder. Since the bottom portionof stackable cartridge 50 includes a similar locater 58 for engagingwith the same standpipe the stackable cartridge 50 and stackablecartridge 70 can be maintained in the same orientation with respect toeach other and to the bulk feeder to provide fluid alignment between thestackable cartridges as water flow into the bottom inlet of stackablecartridge 50 and out the outlet port 75 in top stackable cartridge 70.

FIG. 5 shows a bottom perspective view of stackable cartridge 70, whichmay be used as a halogen stackable cartridge 70 revealing a fluid porthaving set of openings 29 with the fluid port centrally located inbottom member 73. Port 29 permits ingress and egress of fluids thereinwhile retaining a halogen in solid form therein.

FIG. 7 shows a sectional view of a prior art bulk feeder 10, which hasbeen converted to a two biocide feeder, with the stackable cartridge 70and the stackable cartridge 50 in section therein. The stackablecartridge 70 is stacked is a spaced condition on top of the cartridge 50to form a diametrical fluid passage 81 therebetween. When the stackablecartridges 50 and 70 are located in a stacked condition the fluid inlet29 in top member 70 is in axial fluid alignment with fluid outlet 53 inbottom member 51 of the cartridge mineral dispenser 50. In addition thecartridge 50 is positioned in the bottom of bulk feeder chamber 20 suchthat fluid from inlet 16 flows not only into the diametrical passage way81 but also into the chamber 82 formed between the outside of stackablecartridge 50 and the inside wall 11 a of housing 11 and the chamberlocated below cartridge 50. Thus both parallel and series flow exists inthis arrangement.

To appreciate the flow of water through a bulk feeder 10, which containsthe stackable cartridge dispensers 50 and 70, reference should be madeto FIG. 7, which shows multiple sets of arrows to indicate the flow ofwater into and through the stacked dispensing cartridges 50 and 70. FIG.7 shows that water from the main line venturi 13 enters the bulk feederchamber 20 through the side inlet 16. The flow of water then separateswith some of the water flowing into and through a diametrical passage 81located between the top of stackable cartridge 50 and the bottom ofstackable cartridge 70 while some of the water flows into the bulkfeeder lower chamber 82, which contains the stackable cartridge 50. Inthis example the stackable cartridge 50 contains a source of metal ions85 such as a batch of minerals in granular form. The water in chamber 82flows upward through the minerals 85 which are located in chamber 86 ofstackable cartridge 50 thereby releasing metal ions into the water inchamber 86. A portion of the water in chamber 82 flows axially upwardthrough top outlet 53 of cartridge 50 and into chamber 87 through thebottom inlet 29 of halogen cartridge 70 where the water contacts ahalogen such as solid chlorine pucks or tablets 91 thereby releasingchorine into the water. The water level in chamber 87 is indicated bywater line 87 a with a portion of the pucks or tablets 91 located belowthe water line. The water, which is chlorinated through the dissolutionof the tablets or pucks therein, is then discharged though outlet 75into an outlet passage 23 a in stand pipe 23. In addition to waterflowing through the chlorine tablets 91 a portion of the water fromdiametrical passage 81 and chamber 82 can flow upward outside ofcartridge 50 and cartridge 70 until it discharges through the standpipe23. The flow of water through the fluid resistance provided by stackedcartridges 50 and 70 and the contents therein results in the level ofhalogen to be maintained at lower levels using only the existing controlvalve 17 than if the tablets or pucks where placed in chamber 20 withoutthe stackable cartridges therein. Thus the placement of the stackedcartridges 50 and 70, which are located in a flow path as shown in FIG.7, provides more accurate control of the level of halogen delivered bythe bulk feeder than if the halogen tablets were located in the openchamber 20. In addition, although the stackable cartridges contain nocontrol valve the flow resistance of the stackable cartridges allows oneto maintain a lower level of halogen using the existing control valve ofthe feeder since the stackable cartridges eliminates a direct flow pathinto and through the bulk halogen, which has been believed to be atleast a partial cause of a problem of over halogenation with bulkhalogen feeders.

To illustrate the benefits obtained with the use of the stackablecartridges in comparison to a feeder without stackable cartridgesreference should be made to FIG. 8. FIG. 8 a graph of the chlorineoutput of a bulk feeder as a function of the bulk feeder control valvesetting under bulk feeder conditions and the chlorine output of a bulkfeeder as a function of the bulk feeder control valve setting when twointeractive stackable cartridges are located in the chamber of the bulkfeeder. Line 92 represents the chlorine output in ounces/per hour as afunction of the position or setting of the control valve 17 in the bulkfeeder mode i.e. using tablets or pucks of halogens in the bulk feederas shown in FIG. 1. Located below line 92 is a dashed line representinga second chlorine output line 91, which represents a desired maximumchlorine output rate and dashed line 90, which represents a minimumchlorine output rate that should be maintained by the feeder in order toproperly control the level of halogen so as to avoid conditions thatwould lead to under halogenation or under halogenation of the body ofwater when a halogen is used in conjunction with a second biocide suchas a source of metal ions. As evident from the chlorine output 92obtained with bulk feeder control valve, the use of the bulk feedercontrol valve 17 alone lacks the ability to reduce the chlorine deliveryrates to delivery rates which would fall between line 91 and line 90.

Located between chlorine output line 91 and chlorine output line 90 is athird chlorine output line 93 which represents the actual chlorineoutput of the bulk feeder 10 obtainable with a set of interactingstackable cartridges 50 and 70 located in fluid series in the chamber ofa bulk feeder. More specifically, the output 93 reflects bulk feeder 10with a first stackable cartridge 50, which contains a source of mineralssuch as a source of metal ions therein, and a second stackable cartridge70, which contains a biocide such as chlorine in bulk form with the flowof water directed through both stackable cartridges. As can be seen fromFIG. 8 the use of the two interacting stackable cartridges 50 and 70provides more precise control of the chlorine output rate since thechlorine output rate is delivered at a much lower rate as a function ofthe control valve setting. Thus, using the same bulk feeder 10 withstackable cartridges 70 and 50 and the same settings of the bulk feedercontrol valve 17 one can obtain a much lower chlorine level output rateand a finer control of the chlorine output from a chamber 87 of the bulkfeeder 10 as evidenced by the more gradual slope of line 93 as opposedto the slope of line 92. Although, not fully understood the stackablecartridges 50 and 70, which both contain static inlet and outletopenings, are believed to provide an interaction and flow resistancethat allows one to lower the delivery rate of chlorine as well asprovide better control of the delivery rate and consequently avoidconditions which may cause over chlorination even though the bulk feedercontrol valve 17 remains the same. In addition the stacked cartridgesystem allows one to maintain a lower level of halogen in the body ofwater which makes it suitable for a system that uses a second biocide.

FIG. 9 shows an example of prior art bulk feeder 30 with a slightlydifferent set of stackable cartridges 100 and 110 located in a stackedcondition therein. The bulk feeder 30 is characterized by lackinginternal features for maintaining the stackable cartridges 100 and 110in fluid alignment with each other and with an inlet from the controlvalve 34.

FIGS. 10-12 show the bottom stackable cartridge 110 and FIGS. 13-15shows the top stackable cartridge 100. Bottom stackable cartridge 110comprises an annular housing 111 having a top member 112 with a centralaxial fluid passage 115 extending therethrough and a feature or locatercomprising a top port 116 for engagement with a feature or locater ofcartridge 100. In the example shown the spout 104 on stackable cartridge100 provides a flow path between a chamber 132 (FIG. 9) in cartridge 110and a chamber 131 (FIG. 9) in cartridge 100 as well as a feature orlocater for maintaining the fixed rotational alignment of cartridge 100with respect to cartridge 110 and correspondingly the fluid alignment ofcartridge 100 to cartridge 110.

FIG. 9 shows the lower annular housing 113 of stackable cartridge 110engages a bottom member 31 a on feeder housing 31 to support thecartridge 110 in an upright or vertical position on the bottom of thebulk feeder 30, however, the lack of features which could lockinglyengage the housing 30 precludes aligning an inlet of the cartridge 110with the inlet 42 a of the bulk feeder 30. Instead cartridge 110includes a bottom inlet comprising a set of circumferential spaced ports119 with an annular support 114 for engagement with the bottom surface31 b of bulk feeder 30. The set of ports 119 extend around a peripheryof housing 113, which as shown in FIG. 9 are spaced from the interiorwall 31 a to form an annular chamber 133 so that the lower portion ofhousing 113 occupies less than an entire volume of the lower portion ofthe bulk feeder to enable water enter housing 31 to flow into annularchamber 133 before entering the peripheral bottom inlet port 119 incartridge 110. The annular chamber 133 allows the cartridge 110 to beplaced in the bottom of bulk feeder 30 without the need for a locater orfeature to maintain a fixed rotational position of the cartridge 110with respect to the bulk feeder 30 since fluid can flow into thecartridge 110 from all sides of the cartridge through the peripherallyspaced ports 119. That is, the first stackable cartridge 110 includes acylindrical surface setback 113 of a lower portion of the firstcylindrical cartridge 110 from the top portion of the first stackablecartridge to create an annular fluid chamber 133 between a bulk feedersidewall 31 a and the cylindrical surface setback of the first stackablecartridge to permit flow in the chamber 133 around the lower portion ofthe first stackable feeder 110 before the water enters the bottom ofstackable cartridge through the bottom peripheral ports 19, which arespaced around the exterior of the stackable cartridge 110.Correspondingly, the cylindrical spacing of the upper portion of firststackable cartridge 110 from the sidewall 31 a of the bulk feeder 30 isdimensioned so as to be able to maintain the first stackable cartridge110 in a stable upright position with clearance therebetween to allowthe first stackable cartridge to be removed from the bulk feeder withoutthe aid of tools when either or both of the stackable cartridges need tobe replaced.

FIGS. 13-15 show an example of an upper stackable cartridge 100, whichnormally contains a halogen such as bulk chlorine or bulk brominetablets therein, having a cylindrical side wall 102 with a closed top101 and a bottom member 103 having a set of centrally located ports 105and a locater 104 comprising a neck or spout having a fluid passage 104a therein. The purpose of locater 104 is to maintain the alignment ofthe outlet port 116 in stackable cartridge 110 with the inlet fluidpassage 104 a so that water that flows through minerals 134, which arelocated in stackable cartridge 110 (see FIG. 7) can be directed into thechamber 131 of stackable cartridge 100 to contact the halogen tablets130 located therein. The set of openings or ports 105 in stackablecartridge 100 permit flow of water out of chamber 131 but aresufficiently small so as to prevent tablets or pucks of a halogen fromfalling therethrough.

FIG. 9 shows the interacting of stackable cartridge 100 and stackablecartridge 110 when the cartridges are located in chamber 35 of prior artbulk feeder 30. Both the stacked dispensing cartridges and the bulkfeeder are shown in section to reveal the flow patterns through thestackable cartridges. The bulk halogen 130, which normally is located inchamber 35 of the bulk feeder (see FIG. 2), is now located in chamber131 of stackable cartridge 100. The source of metal ions, which was notfound in the bulk feeder 30 is now located in annular chamber 132 instackable cartridge 110.

In operation of the stackable cartridge 100 and stackable cartridge 110the existing unmodified control valve 34 of bulk feeder 30 directs waterthrough pipe 42 and the inlet 42 a and into an annular plenum chamber133 in bulk feeder 30. The water enters the bottom of cartridge 110 byflowing radially inward through the peripheral inlet openings 119 andinto the minerals 134 therein. Thus, in cartridge 110 the water flowsupward through the minerals 131 and out of chamber 132 through the topport 116 of stackable cartridge 110. The water then enters cartridge 100through inlet 104 and circulates upward through the bulk halogen tablets130, which are located in chamber 131 of stackable cartridge 100. Thewater which then picks up the halogen from the halogen tablets thereinflows out of chamber 131 though outlet ports 105, which are located inaxial alignment with the axial passage 115 in stackable cartridge 110.The water, with the halogen therein, flows through the bulk feederoutlet 43 where it enters the main line.

Thus, in the example shown in FIG. 9 a stackable cartridge 110containing a batch of minerals 134 includes a top member 112 and abottom member 113 each having an opening (119, 116) for flow of a liquidtherethrough while preventing passage of the minerals therethrough. Thestackable cartridge container 100 containing a batch of halogen in solidform with a bottom member 103 having an inlet 104 for ingress of liquidtherethrough while retaining the halogen in solid form therein and anoutlet located below a top of the halogen cartridge 100 with the halogencartridge 100 stackable on top of the mineral cartridge 110 to provide aflow path therebetween and an axial flow path from the halogen cartridge100 through the mineral dispensing cartridge 110 whereby the liquidflows through the outlet 43. Thus the lower stackable cartridge 110supports the upper stackable cartridge 100 in a stacked condition wherefluid can be directed vertically upward through a first chamber 132 instackable cartridge 110 and into the chamber 131 in stackable cartridge100 where after picking up the biocides from each of the chambers itstarts it return journey to the main line from whence it came.

In each of the above examples the flow of water through the stackablecartridges has been restricted by the materials in the stackablecartridges or by restricted features in the flow path between stackablecartridges.

While the use of two stackable cartridges are shown and described insome cases there may be benefit and advantages to use of multiplestackable cartridges. FIG. 16 shows the feeder of FIG. 9 with threestackable cartridges located in the chamber of the feeder. In thisexample the top stackable cartridge 100 of FIG. 9 has been replaced withtwo stackable cartridges 141 and 140, although other configurations orsizes may be used which when stacked fit within the chamber of thefeeder housing.

In this example the water enters the first stackable cartridge 110through port 42 a of cartridge 110 and flows through minerals 134 andout the top of cartridge 110 and into stackable cartridge 141 through aninlet spout 147 which forms a feature that fits into the opening 116 incartridge 110 to maintain the cartridge 110 and 141 in fluid alignmentwith each other. The water then enters the chamber 159 in stackablecartridge 141 where it contacts a water treatment material 143. Thewater treatment material may be any of a number of different types ofwater treatment materials including an algaecide, a clarifier, a pHadjuster or other materials that are beneficial in maintaining the bodyof water in a safe condition for use by humans. One of the advantages ofthe use of a multiple stackable cartridge system is that different typesof water treatment materials can be delivered continuously. This isparticularly beneficial with a water treatment material such as aclarifier, which is consumed during the operation of the pool and mustbe periodically added to the pool. With the multiple stackablecartridges the clarifier can be added when the stackable cartridges arereplaced to thereby provide release of a clarifier during an extendedperiod of time.

After flowing through the water treatment material 141 the water flowsinto spout 157 of stackable cartridge 140 which forms a feature thatfits into outlet 149 of stackable cartridge 141 to hold the stackablecartridge 140 in fluid alignment with stackable cartridge 141 which isin turn held in fluid alignment with stackable cartridge 110. Althoughspouts and mating openings are shown as features to maintain thestackable cartridges in fluid alignment other features and methods maybe used.

The water enters chamber 145 through spout 157 with the water fillingthe lower portion of chamber 145 as indicated by water line 145 a, i.e.,the interface between the water and the air that is trapped in the topof stackable cartridge 140 by the closed top 146 and the cylindricalsides of stackable cartridge 140. The water flows through the chlorinetablets 130 and then out through a restrictive opening comprising a setof small openings 142 which prevent the tablets of pucks from fallingthrough but allow the dissolved material to flow therethrough. Thecontact between the chlorine tablets and the water in chamber is limitedsince a portion of the chlorine tablets 130 are located above the waterline 145 a. This feature allows one to reduce the rate of dissolution ofthe chlorine tablets since a portion of the chlorine tablets aremaintained in an out of the water and in an undissolved or unerodedcondition during the initial phase of the chlorination. As the chlorinetablets 130 dissolve the tablets that are above the water line graduallyfall below the water line and are dissolved or eroded and directed intothe main line through outlet 142. Thus the water which now containsmaterials from stackable cartridges 110, 157 and 140 then flows downthrough passage 150, passage 115 and opening 43 where it is returned tothe main line.

While the stackable cartridge containing the halogen has been shown asthe top most stackable cartridge it may be located at a differentvertical position.

If it is desired to extend the halogen delivery of the halogen cartridgethe use of a closed chamber with an air pocket to trap air thereinallows one to extend the time before the water comes into contact withthe halogen. However, in some cases one may wish to dispense with theair pocket as a means for extending the delivery of the halogen.

In the event the halogen cartridge was not the last cartridge in aseries of stacked cartridges the water would be directed in and out ofthe stackable cartridge with the halogen but instead of the water goingdirectly to a return line the water would flow upward into anotherstackable cartridge or cartridges before returning to the main line.

FIG. 2A shows a swimming pool 38 using an existing bulk feeder 30, whichcontains two or more cartridges connected to a pool circulation systemcomprising pipe 46, pump 39 and pipe 42 with the output side of bulkfeeder 30 connected to pool 38 through pipe 48. In this example nosystem changes are needed to deliver two or more materials.

We claim:
 1. The method of converting a bulk feeder having an inlet andan outlet to a cartridge system comprising: placing a first stackablecartridge containing a first water treatment material therein with thefirst stackable cartridge having a bottom inlet and a top outlet in alower portion of a chamber in the bulk feeder; and stacking a secondstackable cartridge containing a different water treatment materialtherein in the bulk feeder with the second stackable cartridge having abottom inlet and an outlet with the first stackable cartridge and thesecond stackable cartridge each including a locater to maintain the topoutlet of the first stackable cartridge and the bottom inlet of thesecond stackable cartridge in fluid alignment therebetween and in serieswith each other to direct a flow of fluid from a main line upwardthrough the bottom inlet of the first cartridge, the water treatmentmaterial in the first cartridge and the outlet of the first cartridgeand into the bottom inlet of the second stackable cartridge and thedifferent water treatment material in the second stackable cartridgebefore discharging the water treatment material and the different watertreatment material out of the outlet of the second stackable cartridgeand into the main line.
 2. The method of claim 1 wherein the firststackable cartridge is spaced from a bottom of the chamber of the bulkfeeder to provide a flow chamber thereunder.
 3. The method of claim 1including the step of placing a batch of chlorine or bromine in thesecond stackable cartridge and a source of silver chloride in the firststackable cartridge.
 4. The method of claim 1 including supporting thesecond cartridge on top of the first cartridge through a support oneither said first cartridge or said second cartridge.
 5. The method ofclaim 1 including adjusting a valve on the bulk feeder to maintain thechlorine at about 0.5 ppm or lower in the fluid when the first stackablecartridge and the second stackable cartridge are located in a stackedcondition in the bulk feeder.
 6. The method of claim 1 including thestep of directing the water in the bulk feeder into the bottom inlet ofthe first stackable cartridge and back into the main line through anoutlet located in a third stackable cartridge located in fluidcommunication with the second stackable cartridge.